This invention relates to a sail-type windmill power transfer device for producing electrical or mechanical power in any environment where wind is present. Thus, this invention pertains to the field of natural renewable energy.
The windmill as a device has been utilized by mankind for hundreds of years because of its usefulness in converting wind power into mechanical power and, more recently, into electrical power.
Generally, wind generators can be subdivided into two categories—horizontal axis wind generators (HAWG) and vertical axis wind generators (VAWG), depending on the orientation of the main rotor shaft. A major difference between these subcategories is the fact that, in the case of HAWGs, the main rotor and electrical generator are positioned at the top of the windmill tower, while in the case of VAWGs they are placed close to or on the ground, thus simplifying the latter's construction and reducing the costs of maintenance. Also, HAWGs do not orient themselves toward the wind, which is their main deficiency, and may be less efficient harvesting winds closer to the ground surface where wind is slower. HAWGs used nowadays in modern wind farms tend to have high installation and maintenance costs and may cause visual or noise pollution.
VAWGs, on the other hand, do not need to be pointed toward the wind and operate in an environment where wind direction is not constant in terms of force or direction. Consequently, such turbines do not need to be mounted on high towers but may operate near to the ground or on building rooftops. Like HAWGs, however, the typical VAWG has some drawbacks, including the loss of efficiency due to the drag caused when the blades rotate into the wind. Thus, the objective of this invention is the design of a VAWG that utilizes the strengths of this subcategory of windmill turbines, namely efficiency in construction, operation and maintenance, while minimizing the loss of efficiency associated with the drag of the blades returning into the wind.
In addition, the invention herein proposed offers multiple other improvements over traditional wind generators. It is designed to have few moving parts thus simplifying the processes of its construction and operation, but also increasing the efficiency of harvesting wind power. By the nature of its design it also provides for ease of installation and maintenance, specifically because the proposed wind power transfer device can be positioned closer to the ground surface than many devices on the market today allow for. This invention also allows for the construction of modular wind turbines so that the final design may combine any number or variation of modules, each constructed based on the principles of the invention herein described. Thus, the proposed device is highly versatile as each wind turbine may be tailored in different modular configurations depending on the circumstances. Another major advantage is that this invention incorporates the placement of photovoltaic cells on the blades of the windmill generator to capture solar energy in addition to wind energy so produced.